while driving home from work at 330am, i gave 'er a little to much gas going into 2nd and my back end kicked out a little. i noticed on the rest of the way home, when i accelerate, it now vibrates a little in the rear. almost like trying to make it up a hill at 2k RPMs. im thinking maybe my center bearing on my driveshaft? or i fucked up my rear dif?

 

Does the vibration get worse as your speed increases? Might sound silly, but you may have lost a wheel weight. I crubbed my passenger's side front wheel on my old car and ripped off that crimp-on wheel weight they use when they balance your wheels. Didn't notice it at the time, but whenever i was on the beltway after that, the RF corner would shake like a leaf. You couldn't notice it below about 45mph, and it got worse as speed increased.

 

checked all my wheels, definately not the weights. i also need to add that this stops as speed increases. worst in 1st, bad in 2nd etc. 4th doesnt really do it at all. could a wheel bearing do this? what about a bad dif. mount?

 

Wheel bearing wouldn't go away at higher speeds i don't think. Besides, if a wheel bearing was bad to the point of vibrating badly, the humming would have driven you nuts by now. either way, seems odd for a wheel bearing or diff mount to just "go bad" because you got a little loose around a corner...

 

thats what im sayin. what about a control arm?

 

At this point I'd just be speculating. If it were me I'd throw that sumbitch up on jack stands and start wiggling ****, see if you can narrow it down that way

 

i already tried that =/ its so bad in 1st, almost like both my back tires are locked up and hopping down the road haha

 

Have you figured out this problem yet? I have a similar problem, except that I get vibrations in the steering wheel at highway speeds, only when accelerating. Once I let up off the gas, the car twitches a little, and then the ride gets smooth. Gas again, and the vibrations come back. It doesnt do it all the time though.
By the way, my car is a 2.8 with 5 speed. It also doesnt happen in neutral, and only on the highway.

 

yea i figured it out, but its not your problem. it was my carrier bearing in my driveshaft, when under heavy load (1st gear mainly) the thing moved all around at the hinged point in the middle

 

What did you do ti fix it? There's a few places that are making solid driveshafts for A4's now.